The use of disposable diapers for infant care has become increasingly widespread in recent years, with these disposable products providing substantial advantages and convenience over reuseable diapers. A typical disposable diaper structure includes a layer of liquid-retaining absorbent material sandwiched between a moisture pervious facing layer positioned adjacent the skin of the wearer, and a moisture impervious plastic backing sheet to confine moisture within the absorbent layer.
In the past, the absorbent layer has typically been comprised of batt of loosely compacted cellulosic fibers, usually comminuted wood pulp or "fluff". While such absorbent material is relatively inexpensive and is capable of quickly absorbing liquids, the typical diaper structure including such material is configured such that it detracts from the comfort of the wearer.
Specifically, typical disposable diaper products are relatively thick and exhibit high bulk. Such arrangements were thought to be desirable because consumers showed a preference for thicker diapers in view of their higher absorptive capacity and reduced tendency to leak. Even those products which include hydrocolloid or superabsorbent materials in combination with wood pulp are relatively thick.
The appearance of bulkiness of a diaper is related to the panel thickness and to the volume of the diaper absorbent panel. The volume of the panel affects the comfort of the product as felt by the wearer, typically infants, and also affects consumer preferences.
With regard to wearer comfort, testing has shown that a standing infant of five months of age or older, and weighing approximately 16 pounds and up, has only a very small distance between its upper thighs, typically 0.5 inches or less. As will be appreciated, whatever thickness a diaper exhibits between the infant's legs that is in excess of the child's natural crotch width will necessarily press against the child's thighs, spreading the thighs apart to accommodate the diaper. This unnatural displacement of the child's thighs encumbers the child's mobility, and is typically perceived as uncomfortable.
Further, consumers prefer a snug-fitting diaper not only because of its aesthetic appeal, but also because of the desired ease with which outer clothing can be fit over the diaper. It is therefore preferred that a diaper does not tend to hang low between an infant's legs with a bagging or pouch-like appearance. As will be appreciated, however, in order for the diaper to fit close to the body in the limited space between the thighs, the diaper must fold or corrugate. As a consequence of this multiplying effect of the diaper thickness, undesirable bulk is created in the crotch region which is larger than the natural space provided between the thighs, with the resultant decrease in comfort.
In view of the foregoing, it is desirable to provide a disposable diaper product which is configured to exhibit desirably low bulk for improved fit and comfort, while at the same time exhibiting enhanced absorptive capacity per unit volume of the absorbent diaper panel so that the diaper can be used effectively while minimizing leakage.